The most egregious acts can be downplayed or politely ignored, if the aggrieved party really wishes to avoid war. On the other hand, the smallest provocation can serve as a justification for war, if the aggrieved party wants war.
North Korea regularly shells South Korea, sometimes killing South Korean civilians. It's absolutely a cause for war, and they might indeed be justified, in a sense, with breaking the ceasefire and marching on Pyongyang the next time NK does so. But they will have to live with the war that would cause.
North Korea regularly shells South Korea, sometimes killing South Korean civilians. It's absolutely a cause for war, and they might indeed be justified, in a sense, with breaking the ceasefire and marching on Pyongyang the next time NK does so. But they will have to live with the war that would cause.